feat(bus-mapping): add sanity check for jumpi (#1204)

bus-mapping/src/evm/opcodes.rs

@@ -40,6 +40,7 @@ mod extcodecopy;
 mod extcodehash;
 mod extcodesize;
 mod gasprice;
+mod jumpi;
 mod logs;
 mod mload;
 mod mstore;
@@ -78,7 +79,7 @@ mod memory_expansion_test;
 #[cfg(feature = "test")]
 pub use callop::tests::PrecompileCallArgs;
 
-use self::{pushn::PushN, sha3::Sha3};
+use self::{jumpi::Jumpi, pushn::PushN, sha3::Sha3};
 
 use address::Address;
 use arithmetic::ArithmeticOpcode;
@@ -234,7 +235,7 @@ fn fn_gen_associated_ops(opcode_id: &OpcodeId) -> FnGenAssociatedOps {
         OpcodeId::SLOAD => Sload::gen_associated_ops,
         OpcodeId::SSTORE => Sstore::gen_associated_ops,
         OpcodeId::JUMP => StackPopOnlyOpcode::<1>::gen_associated_ops,
-        OpcodeId::JUMPI => StackPopOnlyOpcode::<2>::gen_associated_ops,
+        OpcodeId::JUMPI => Jumpi::gen_associated_ops,
         OpcodeId::PC => Pc::gen_associated_ops,
         OpcodeId::MSIZE => Msize::gen_associated_ops,
         OpcodeId::GAS => Gas::gen_associated_ops,

bus-mapping/src/evm/opcodes/jumpi.rs

@@ -0,0 +1,49 @@
+use super::Opcode;
+use crate::{
+    circuit_input_builder::{CircuitInputStateRef, ExecStep},
+    Error,
+};
+use eth_types::GethExecStep;
+
+#[derive(Debug, Copy, Clone)]
+pub(crate) struct Jumpi;
+
+impl Opcode for Jumpi {
+    fn gen_associated_ops(
+        state: &mut CircuitInputStateRef,
+        geth_steps: &[GethExecStep],
+    ) -> Result<Vec<ExecStep>, Error> {
+        let geth_step = &geth_steps[0];
+        let mut exec_step = state.new_step(geth_step)?;
+
+        let pc = state.stack_pop(&mut exec_step)?;
+        let condition = state.stack_pop(&mut exec_step)?;
+
+        if let Some(next_step) = geth_steps.get(1) {
+            if condition == 0.into() {
+                assert_eq!(
+                    next_step.pc.0,
+                    geth_step.pc.0 + 1,
+                    "jumpi should not jump: current step {:?} next step {:?}",
+                    geth_step,
+                    next_step
+                );
+            } else {
+                assert_eq!(
+                    next_step.pc.0 as u64,
+                    pc.low_u64(),
+                    "jumpi should jump: current step {:?} next step {:?}",
+                    geth_step,
+                    next_step
+                );
+            }
+        }
+
+        #[cfg(feature = "enable-stack")]
+        for (i, v) in [pc, condition].into_iter().enumerate() {
+            assert_eq!(v, geth_step.stack.nth_last(i)?);
+        }
+
+        Ok(vec![exec_step])
+    }
+}